directional transmission meaning in English

定向传输
定向发射

Design of bi - directional transmission tire pressure monitoring system
双向通讯的轮胎压力监测系统设计
The system realize the bi - directional transmission between remote detection and control unit and the supervision center with the sm transmission function of gsm terminal , meets the requirement that supervision center need to supervise the operation of the power network from remote sites only through gsm communication network
该系统利用gsm终端的短信息传输功能,实现了远端检测控制单元与监测中心之间的双向信息传递,满足了监控中心只需通过gsm通信网络,便可对电力网的运行情况进行远程无线监控需要。